This specification relates to information retrieval.
Conventional information retrieval systems are used to identify a wide variety of resources, for example, images, audio files, web pages, or documents, e.g., news articles. Additionally, search results presented to a user that identify particular resources responsive to a query are typically ranked according to particular criteria.
Conventional image analysis systems can be used to extract features from an image into a feature representation. A representation of an image is a feature vector, where each element of the feature vector is a representation of a feature extracted from the image. All possible feature vectors for an image can define a feature space for the image.